A 2D laser technology-based automatic leveling system and method for a grader

Abstract

The present invention discloses an automatic leveling system and method for motor graders based on 2D laser technology. This system aims to address the problem of existing motor graders requiring the operator to visually adjust the blade height, which affects construction accuracy and efficiency. This problem also leads to excessive blade loading and excessive soil volume when encountering uneven terrain. The system comprises a laser transmitter, a controller, and a blade. The blade is equipped with a lifting mechanism, a support rod, and a laser receiver. The controller is electrically connected to the laser receiver, and is also electrically connected to an electric proportional valve and a display. The system is suitable for leveling motor graders, automatically adjusting the blade height to improve leveling accuracy. The system is simple to operate and reduces operator workload. The blade first performs rough leveling, followed by fine leveling. This prevents excessive blade loading and excessive soil volume without compromising construction accuracy.

Description

Technical Field

[0001] The present invention relates to an automatic leveling system and method for a motor grader based on 2D laser technology, and belongs to the technical field of motor graders. Background Art

[0002] A motor grader is an earth-moving machine that uses a scraper to level the ground. The scraper is mounted between the machine's front and rear axles and can be raised, lowered, tilted, rotated, and extended. Its flexible and accurate movements, easy operation, and high precision leveling make it suitable for constructing roadbeds and pavements, building slopes, and excavating ditches. It can also be used for mixing road mixes, clearing snow, moving bulk materials, and maintaining dirt and gravel roads. To ensure smoothness during construction, the blade position must be controlled during operation to ensure the scraped trench meets the required flatness. This typically requires the driver to visually and empirically adjust the blade height, which does not guarantee accuracy or efficiency.

[0003] When working, existing graders usually require the driver to adjust the blade height based on visual observation and experience, which affects construction accuracy and efficiency. When encountering working conditions with large ground undulations, too much soil is placed under the blade and the soil load is large, which can easily cause the grader to be unable to work and affect the practicality of the device. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide an automatic leveling system and method for a grader based on 2D laser technology to solve the problem that when the grader is working, the driver needs to adjust the blade height based on visual observation and experience, which affects the construction accuracy and efficiency. When encountering working conditions with large ground undulations, there is too much soil under the blade and the soil load is large, which easily causes the grader to be unable to work.

[0005] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present invention provides an automatic leveling system for a grader based on 2D laser technology, comprising a laser transmitter, a controller and a blade, wherein the blade is provided with a lifting mechanism for driving the blade to rise and fall, the blade is provided with a support rod, and the support rod is provided with a laser receiver, the controller is electrically connected to the laser receiver, the controller is electrically connected to an electric proportional valve and a display, and the electric proportional valve is electrically connected to the lifting mechanism.

[0007] Furthermore, there are two support rods and they are separately arranged on both sides of the scraper, and there are two laser receivers and they are separately arranged on the two support rods.

[0008] Furthermore, the laser emitter is provided with a tripod for adjusting the height of the laser emitter.

[0009] Furthermore, the lifting mechanism includes a left blade lifting cylinder and a right blade lifting cylinder, and both the left blade lifting cylinder and the right blade lifting cylinder are electrically connected to the electric proportional valve.

[0010] In a second aspect, the present invention provides an automatic leveling method for a grader based on 2D laser technology, which adopts the automatic leveling system for a grader based on 2D laser technology described in any one of the first aspects, comprising:

[0011] Step A: Determine the reference surface to determine the receiving laser point and the center point;

[0012] Step B: Setting the display to automatic mode, setting the rough leveling reference correction value a, the correction value offset b, the first allowable error range, and the second allowable error range, wherein the rough leveling reference correction value a is greater than the correction value offset b;

[0013] Step C: Calculate the offset signal based on the received laser point and the center point, and compare it with the rough leveling reference correction value a to obtain the difference. If the difference is within the first allowable error range, the work is completed; if the difference is not within the first allowable error range, adjust the height of the scraper until the difference is within the first allowable error range;

[0014] Step D: Calculate the new leveling reference correction value c based on the rough leveling reference correction value a and the correction value offset b, and replace the rough leveling reference correction value a in step C with the new leveling reference correction value c. If the new leveling reference correction value c is less than the correction value offset b, the work is completed; if the new leveling reference correction value c is greater than the correction value offset b, repeat steps C and D until the new leveling reference correction value c is less than the correction value offset b.

[0015] Step E: Calculate the offset signal based on the received laser point and the center point. If the offset signal is within the second allowable error range, the work is completed. If the offset signal is not within the second allowable error range, adjust the height of the blade until the offset signal is within the second allowable error range.

[0016] Furthermore, determining the reference plane includes:

[0017] Set the display to manual mode;

[0018] Place the blade horizontally on the reference point obtained from engineering surveying;

[0019] Place a laser transmitter on the front of the grader;

[0020] Turn on the laser transmitter and adjust the height of the laser transmitter until the green light on the laser receiver turns on;

[0021] Fix the height of the laser transmitter. The horizontal plane where the laser transmitter is located is the reference plane.

[0022] Furthermore, the laser receiving point refers to the position when the laser receiver receives the laser transmitter;

[0023] The center point refers to the center point of the position when the laser receiver receives the laser transmitter in the reference plane, and is used as a reference point.

[0024] Furthermore, the new leveling benchmark correction value c is calculated using the following formula:

[0025] c=a-be

[0026] Where: c represents the new leveling reference correction value, a represents the rough leveling reference correction value, b represents the correction value offset, and e represents the number of times step C is performed.

[0027] Furthermore, in step C, the height of the blade is adjusted until the difference is within the first allowable error range:

[0028] The controller calculates the electric proportional valve opening signal based on the difference and outputs it;

[0029] The electric proportional valve controls the lifting mechanism stroke according to the opening signal, thereby controlling the lifting height of the blade;

[0030] The controller calculates the offset signal between the received laser point and the center point in real time, and calculates the difference between the offset signal and the rough leveling reference correction value a, repeats step C and controls the height of the scraper until the difference is within the first allowable error range.

[0031] Furthermore, in step E, the height of the blade is adjusted until the offset signal is within the second allowable error range:

[0032] The controller calculates the electric proportional valve opening signal based on the offset signal and outputs it;

[0033] The electric proportional valve controls the lifting mechanism stroke according to the opening signal, thereby controlling the lifting height of the blade;

[0034] The controller calculates the offset signal between the received laser point and the center point in real time, repeats step E and controls the height of the scraper until the offset signal is within the first allowable error range.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. This 2D laser-based automatic leveling system and method for a motor grader uses a laser transmitter, laser receiver, controller, electric proportional valve, and lifting mechanism to coordinate with each other. Using 2D laser technology, it sets a precise reference surface, detects the height deviation between the blade and the reference surface in real time, and adjusts the blade's height accordingly, ensuring the blade reaches the required reference surface height. This automatically levels the blade, improving leveling accuracy. The system is simple to operate, eliminating the need for the driver to visually estimate the blade height based on experience, reducing the driver's workload and ensuring construction accuracy and efficiency.

[0037] 2. When the ground is undulating, the present invention can set the rough leveling reference correction value a and the correction value offset b so that the blade first performs rough leveling and then fine leveling. Under the premise of not affecting the construction accuracy, it avoids too much soil under the blade and excessive soil load, which may easily cause the grader to be unable to work, thereby ensuring the practicality of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 2. It is a schematic structural diagram of an automatic leveling system for a grader based on 2D laser technology according to an embodiment of the present invention;

[0039] Figure 2 2. This is a schematic diagram of the system structure of an automatic leveling system for a grader based on 2D laser technology according to an embodiment of the present invention;

[0040] Figure 3 This is a flow chart of an automatic leveling method for a grader based on 2D laser technology provided according to an embodiment of the present invention.

[0041] In the figure: 1. Laser transmitter; 2. Laser receiver; 3. Support pole; 4. Shovel; 5. Tripod. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0044] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0045] Example 1:

[0046] like Figure 1 As shown, the present invention provides an automatic leveling system for a grader based on 2D laser technology, including a laser transmitter 1, a controller and a blade 4. The blade 4 is provided with a lifting mechanism for driving the blade 4 to rise and fall, and a support rod 3 is provided on the blade 4. A laser receiver 2 is provided on the support rod 3. The controller is electrically connected to the laser receiver 2, and the controller is electrically connected to an electric proportional valve and a display. The electric proportional valve is electrically connected to the lifting mechanism; there are two support rods 3 and they are respectively arranged on both sides of the blade 4, and there are two laser receivers 2 and they are respectively arranged on the two support rods 3; the laser transmitter 1 is provided with a tripod 5 for adjusting the height of the laser transmitter 1; the lifting mechanism includes a left blade lifting cylinder and a right blade lifting cylinder, and the left blade lifting cylinder and the right blade lifting cylinder are both electrically connected to the electric proportional valve.

[0047] Specifically, the laser transmitter is arranged in front of the grader; the laser receiver 2 communicates data with the controller, the controller is connected to the electric proportional valve, the controller controls the electric proportional valve, the electric proportional valve is connected to the left blade lifting cylinder and the right blade lifting cylinder, controls the stroke of the left blade lifting cylinder and the right blade lifting cylinder, the left blade lifting cylinder and the right blade lifting cylinder are connected to the blade 4, and then controls the lifting height of the blade 4.

[0048] The display is connected to the controller for data display and parameter setting, and data communication is carried out with the controller via the CAN bus. When determining the reference surface, the laser transmitter 1 transmits a 360° rotating laser. When the grader is leveling the ground, the transmitted laser is used as the reference surface, so that the laser receiver 2 receives the laser in all directions. After receiving the transmitted laser, the laser receiver 2 uses the center point of the laser receiver 2 as the reference point to calculate the offset between the received laser point and the center point, that is, the height deviation between the blade 4 and the working reference surface. The laser receiver 2 transmits the blade 4 offset signal to the controller via the CAN bus, and the controller calculates the opening size of the electric proportional valve and calculates the calculated value. The calculated opening signal is transmitted to the electric proportional valve, and the electric proportional valve controls the stroke of the left and right blade lifting cylinders according to the opening signal, thereby controlling the lifting height of the blade 4; after the height of the blade 4 is adjusted, the height of the laser receiver 2 changes, and the laser receiver 2 detects the offset between the received laser point and the center point in real time. The controller continuously calculates the electric proportional valve opening signal based on the new offset until the center point of the laser receiver 2 reaches the reference plane position; the display is connected to the controller to display the height of the blade 4 from the reference plane, and to set the rough leveling reference correction value, correction value offset, first allowable error range and second allowable error range.

[0049] Example 2:

[0050] like Figure 2-3 As shown, the present invention provides an automatic leveling method for a grader based on 2D laser technology, which adopts the automatic leveling system for a grader based on 2D laser technology described in any one of the first embodiments, including:

[0051] Step A: Determine the reference surface to determine the receiving laser point and the center point;

[0052] The laser receiving point refers to the position when the laser receiver 2 receives the laser transmitter 1;

[0053] The center point refers to the center point of the position when the laser receiver 2 receives the laser transmitter 1 in the reference plane, and it is used as the reference point

[0054] Wherein, determining the reference plane includes:

[0055] Set the display to manual mode;

[0056] Place the blade 4 horizontally on the reference point obtained from engineering surveying;

[0057] In an open space in front of the grader that does not affect the construction, set up the tripod 5 and place the laser transmitter 1 horizontally;

[0058] Turn on the laser transmitter 1 and adjust the height of the laser transmitter 1 until the green light of the laser receiver 2 turns on, indicating that the reference scanning point has been reached;

[0059] Fix the tripod 5 to fix the height of the laser emitter 1. At this time, the horizontal plane where the laser emitter 1 is located is the reference plane, and the ground leveling operation can be carried out.

[0060] Step B: Set the display to automatic mode, set the rough leveling reference correction value a, the correction value offset b, the first allowable error range, and the second allowable error range, wherein the rough leveling reference correction value a is greater than the correction value offset b; keep the laser transmitter 1 in the transmitting state. When working, the laser transmitter 1 is located in front of the grader. After receiving the laser, the laser receiver 2 outputs an offset signal between the receiving laser point and the center point, and sends the offset signal to the controller via the CAN bus;

[0061] Among them, rough leveling is performed when the rough leveling reference correction value a is greater than or equal to the correction value offset b, and fine leveling is performed when the rough leveling reference correction value a is less than the correction value offset b; the first allowable error range and the second allowable error range are obtained by repeated debugging based on actual conditions. When the error is too large, the accuracy requirement is not met, and when the error is too small, control overshoot jitter will occur.

[0062] Step C: Rough leveling: Calculate the offset signal based on the received laser point and the center point, and compare it with the rough leveling reference correction value a to obtain the difference. If the difference is within the first allowable error range, the rough leveling work is completed; if the difference is not within the first allowable error range, adjust the height of the blade 4 until the difference is within the first allowable error range;

[0063] In step C, the height of the blade 4 is adjusted until the difference is within the first allowable error range:

[0064] The controller calculates the electric proportional valve opening signal based on the difference and outputs it;

[0065] The electric proportional valve controls the stroke of the left blade lifting cylinder and the right blade lifting cylinder according to the opening signal, thereby controlling the lifting height of the blade 4;

[0066] After the blade 4 adjusts its height, the controller calculates the offset signal between the received laser point and the center point in real time, and calculates the difference between it and the rough leveling reference correction value a, repeats step C and controls the height of the blade 4 until the difference is within the first allowable error range, completing the rough leveling work.

[0067] Step D: Perform the next leveling operation. Calculate a new leveling reference correction value c based on the rough leveling reference correction value a and the correction value offset b. Replace the rough leveling reference correction value a in step C with the new leveling reference correction value c. If the new leveling reference correction value c is less than the correction value offset b, the operation is completed and fine leveling is performed. If the new leveling reference correction value c is greater than the correction value offset b, repeat steps C and D until the new leveling reference correction value c is less than the correction value offset b.

[0068] The new leveling benchmark correction value c is calculated using the following formula:

[0069] c=a-be

[0070] Where: c represents the new leveling reference correction value, a represents the rough leveling reference correction value, b represents the correction value offset, and e represents the number of times step C is performed.

[0071] Step E: Fine leveling: Calculate the offset signal based on the received laser point and the center point. If the offset signal is within the second allowable error range, the fine leveling is completed. If the offset signal is not within the second allowable error range, adjust the height of the blade 4 until the offset signal is within the second allowable error range.

[0072] In step E, the height of the blade 4 is adjusted until the offset signal is within the second allowable error range:

[0073] The controller calculates the electric proportional valve opening signal based on the offset signal and outputs it;

[0074] The electric proportional valve controls the stroke of the left blade lifting cylinder and the right blade lifting cylinder according to the opening signal, thereby controlling the lifting height of the blade 4;

[0075] After the blade 4 adjusts its height, the controller calculates the offset signal between the received laser point and the center point in real time, repeats step E and controls the height of the blade 4 until the offset signal is within the first allowable error range, and then the height of the blade 4 remains unchanged, the fine leveling work is completed, and the ground leveling operation is completed.

[0076] Among them, the parameters of the rough leveling reference correction value a, the correction value offset b, the first allowable error range and the second allowable error range are set through the display according to the actual working conditions on site. The present invention cooperates with the laser transmitter 1, the laser receiver 2, the controller, the electric proportional valve, the lifting mechanism and other structures, sets a precise reference surface through 2D laser technology, detects the height deviation between the blade 4 and the reference surface in real time, adjusts the lifting height of the blade 4 according to the height deviation, and makes the blade 4 reach the reference surface height requirement, thereby automatically leveling the height of the blade 4, improving the leveling accuracy, and simple operation. The driver does not need to adjust the height of the blade 4 based on visual observation of the height of the blade 4 based on experience, which reduces the driver's workload and ensures the accuracy and efficiency of construction.

[0077] When the present invention encounters a working condition where the ground is undulating greatly, the rough leveling reference correction value a and the correction value offset b can be set so that the blade 4 first performs a rough leveling operation. After the rough leveling operation is completed, the ground is first leveled once, and then fine leveling operation is performed, and the ground is leveled again. Under the premise of not affecting the construction accuracy, it is avoided that the blade 4 puts down too much soil at one time, and the soil load is too large, which easily causes the grader to be unable to work and affects the use effect of the device, and ensures the practicality of the device.

[0078] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An automatic leveling system for a grader based on 2D laser technology, characterized in that: The invention comprises a laser transmitter (1), a controller and a scraper (4), wherein the scraper (4) is provided with a lifting mechanism for driving the scraper (4) to move up and down, the scraper (4) is provided with a support rod (3), the support rod (3) is provided with a laser receiver (2), the controller is electrically connected to the laser receiver (2), the controller is electrically connected to an electric proportional valve and a display, and the electric proportional valve is electrically connected to the lifting mechanism; An automatic leveling method for a land grader based on 2D laser technology, comprising: Step A: Determine the reference surface to determine the receiving laser point and the center point; Step B: Setting the display to automatic mode, setting the rough leveling reference correction value a, the correction value offset b, the first allowable error range, and the second allowable error range, wherein the rough leveling reference correction value a is greater than the correction value offset b; Step C: Calculate the offset signal based on the received laser point and the center point, compare it with the rough leveling reference correction value a to obtain a difference, if the difference is within the first allowable error range, the work is completed; if the difference is not within the first allowable error range, adjust the height of the blade (4) until the difference is within the first allowable error range; Step D: Calculate a new leveling reference correction value c based on the rough leveling reference correction value a and the correction value offset b, and replace the rough leveling reference correction value a in step C with the new leveling reference correction value c. If the new leveling reference correction value c is less than the correction value offset b, the work is completed; if the new leveling reference correction value c is greater than the correction value offset b, repeat steps C and D until the new leveling reference correction value c is less than the correction value offset b. Step E: Calculate the offset signal based on the received laser point and the center point. If the offset signal is within the second allowable error range, the work is completed. If the offset signal is not within the second allowable error range, adjust the height of the blade (4) until the offset signal is within the second allowable error range.

2. The automatic leveling system for a grader based on 2D laser technology according to claim 1 is characterized in that: There are two support rods (3) which are separately arranged on both sides of the scraper (4), and there are two laser receivers (2) which are separately arranged on the two support rods (3).

3. The automatic leveling system for a grader based on 2D laser technology according to claim 1, characterized in that: The laser emitter (1) is provided with a tripod (5) for adjusting the height of the laser emitter (1).

4. The automatic leveling system for a grader based on 2D laser technology according to claim 1 is characterized in that: The lifting mechanism includes a left blade lifting cylinder and a right blade lifting cylinder, and both the left blade lifting cylinder and the right blade lifting cylinder are electrically connected to the electric proportional valve.

5. The automatic leveling system for a grader based on 2D laser technology according to claim 1 is characterized in that: Determining the reference surface includes: Set the display to manual mode; Place the blade (4) horizontally on the reference point obtained from engineering surveying; Place a laser transmitter (1) in front of the grader; Turn on the laser transmitter (1) and adjust the height of the laser transmitter (1) until the green light on the laser receiver (2) turns on; The height of the laser emitter (1) is fixed, and the horizontal plane where the laser emitter (1) is located is the reference plane.

6. The automatic leveling system for a grader based on 2D laser technology according to claim 1, characterized in that: The laser receiving point refers to the position when the laser receiver (2) receives the laser transmitter (1); The center point refers to the center point of the position when the laser receiver (2) receives the laser transmitter (1) in the reference plane, and is used as a reference point.

7. The automatic leveling system for a grader based on 2D laser technology according to claim 1, characterized in that: The new leveling benchmark correction value c is calculated using the following formula: ； Where: c represents the new leveling reference correction value, a represents the rough leveling reference correction value, b represents the correction value offset, and e represents the number of times step C is performed.

8. The automatic leveling system for a grader based on 2D laser technology according to claim 1, characterized in that: In step C, the height of the blade (4) is adjusted until the difference is within the first allowable error range: The controller calculates the electric proportional valve opening signal based on the difference and outputs it; The electric proportional valve controls the stroke of the lifting mechanism according to the opening signal, thereby controlling the lifting height of the blade (4); The controller calculates the offset signal between the received laser point and the center point in real time, and calculates the difference between the offset signal and the rough leveling reference correction value a, repeats step C and controls the height of the scraper (4) until the difference is within the first allowable error range.

9. The automatic leveling system for a grader based on 2D laser technology according to claim 1, characterized in that: In step E, the height of the blade (4) is adjusted until the offset signal is within the second allowable error range: The controller calculates the electric proportional valve opening signal based on the offset signal and outputs it; The electric proportional valve controls the stroke of the lifting mechanism according to the opening signal, thereby controlling the lifting height of the blade (4); The controller calculates the offset signal between the received laser point and the center point in real time, repeats step E and controls the height of the scraper (4) until the offset signal is within the first allowable error range.

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